A268771 Number of nX5 0..2 arrays with some element plus some horizontally, vertically, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

96, 248, 1524, 10340, 64112, 387146, 2258084, 12951796, 73011192, 406925194, 2244513800, 12281806624, 66734787464, 360505595710, 1937557458852, 10367717536488, 55261185262316, 293537189567482, 1554428843176696

Offset

1,1

Comments

Column 5 of A268774.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 4*a(n-1) +28*a(n-2) -62*a(n-3) -314*a(n-4) +78*a(n-5) +867*a(n-6) +6*a(n-7) -859*a(n-8) +46*a(n-9) +215*a(n-10) -8*a(n-11) -16*a(n-12) for n>14

Example

Some solutions for n=4
..1..2..1..2..2. .2..1..2..1..2. .0..0..1..1..0. .2..2..1..2..1
..2..2..2..2..2. .2..1..2..2..2. .0..0..0..0..0. .2..2..2..2..2
..1..2..2..2..1. .2..2..2..2..2. .0..1..0..1..0. .2..1..2..2..2
..2..2..2..2..1. .2..2..2..2..1. .0..0..0..0..0. .2..2..1..2..1

Crossrefs

Cf. A268774.

Sequence in context: A125511 A124106 A304510 * A202898 A202891 A232939

Adjacent sequences: A268768 A268769 A268770 * A268772 A268773 A268774

Keyword

nonn

Author

R. H. Hardin, Feb 13 2016

Status

approved